Results 51 to 60 of about 151,165 (141)

cx2204/stellar-radius: stellar radius microphysics

open access: yes, 2022
Full Changelog: https://github.com/cx2204/stellar-radius/commits/v1.
cx2204
core   +1 more source

Space Weather Impact of Three Solar Flares Observed by the POEMAS Telescope at 45 and 90 GHz

open access: yesJournal of Geophysical Research: Space Physics, Volume 130, Issue 11, November 2025.
Abstract Solar flares are often associated with coronal mass ejections (CMEs) that, when directed toward Earth, can disrupt the magnetosphere and impact space weather. In this study, we investigate three long‐duration solar flares observed in 2012 by the POlarization Emission of Millimeter Activity at the Sun (POEMAS) telescopes at 45 and 90 GHz.
Adriana Valio   +4 more
wiley   +1 more source

Predicting Photospheric Ultraviolet Emission from Stellar Evolutionary Models

open access: yesThe Astrophysical Journal
Stellar ultraviolet (UV) emission serves as a crucial indicator for estimating magnetic activity and evaluating the habitability of exoplanets orbiting stars.
Song Wang   +3 more
doaj   +1 more source

The High-energy Spectrum of the Young Planet Host V1298 Tau

open access: yesThe Astronomical Journal, 2023
V1298 Tau is a young pre-main-sequence star hosting four known exoplanets that are prime targets for transmission spectroscopy with current-generation instruments. This work pieces together observations from the NICER X-ray telescope, the Space Telescope
Girish M. Duvvuri   +6 more
doaj   +1 more source

Solar Flare Activity, 1937–2024: Introducing the New Hemispheric Solar Flare Index (hSFI) in the Context of 2024's Major Solar Storm Events

open access: yesSpace Weather, Volume 23, Issue 11, November 2025.
Abstract A new daily composite of the solar flare index (SFI) and the hemispherically‐resolved versions (hSFI) are presented for 1937 to 2024. The data set confirms that the northern hemisphere (NH) dominated solar flare activity during Solar Cycles 17 to 21, but that the southern hemisphere has dominated from Solar Cycle 22 to present.
V. M. Velasco Herrera   +14 more
wiley   +1 more source

Influence of surface stressing on stellar coronae and winds [PDF]

open access: yes, 2013
STFC funding has supported this research.The large-scale field of the Sun is well represented by its lowest energy (or potential) state. Recent observations, by comparison, reveal that many solar-type stars show large-scale surface magnetic fields that ...
Morin, J.   +13 more
core   +1 more source

Far-ultraviolet Emission Line Investigation of Flares on AU Mic

open access: yesThe Astrophysical Journal
The role of nonthermal proton energy transportation during solar and stellar flares is largely unknown; a better understanding of this physical process will allow us to rectify longstanding deficiencies in flare models.
Adalyn Gibson   +2 more
doaj   +1 more source

Comparison of Solar Imaging Feature Extraction Methods in the Context of Space Weather Prediction With Deep Learning‐Based Models

open access: yesJournal of Geophysical Research: Machine Learning and Computation, Volume 2, Issue 3, September 2025.
Abstract Recently, many machine learning‐based models have been developed to predict geomagnetic activity several days in advance directly from space‐borne solar imaging. To better understand and improve these models, we compare dimensionality reduction techniques to extract abstract features from solar images for space weather‐related downstream tasks.
Maria Tahtouh   +5 more
wiley   +1 more source

On the Origin and Evolution of Stellar Chromospheres, Coronae and Winds [PDF]

open access: yes, 1997
The final report discusses work completed on proposals to construct state-of-the-art, theoretical, two-component, chromospheric models for single stars of different spectral types and different evolutionary status.
Musielak, Z. E.
core  

Double-edged Sword: The Influence of Tidal Interaction on Stellar Activity in Binaries

open access: yesThe Astrophysical Journal
Using the LAMOST DR7 low-resolution spectra, we carried out a systematic study of stellar chromospheric activity in both single and binary stars. We constructed a binary sample and a single-star sample, mainly using the binary belt and the main sequence ...
Yuedan Ding   +6 more
doaj   +1 more source

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